The present invention concerns a heat exchanger for cooling cracked gas.
The gas is produced by thermally cracking hydrocarbons in a cracking furnace. Cracking furnaces have a number of externally heated cracking pipes. The hydrocarbons are conveyed through the pipes accompanied by steam. The gas leaves the pipe at approximately 800.degree. to 850.degree. C. and must be cooled very rapidly to stabilize its molecular composition. This is done in coolers by transmitting heat from the gas to a highly compressed evaporating water.
Cracked-gas cooling systems wherein each pipe extending out of the furnace communicates with its own cooler are known. Each cooler can have one or more pipes. The pipes can all be accommodated in one jacket or be double. Since the pipes leaving the furnace are usually aligned relatively close together, all of the coolers can be combined into a module, constituting a linear cooler. Coolant is introduced and removed at the ends of the pipes and by way of water-filled compartments, which can be elliptical or cylindrical. The compartments communicate with all the pipes in the system.